The swimming pools can be of the ground-level type, in which the water surface is substantially at the same level as the walking surface, or their base can rest on the walking surface.
The ground-level type entails providing an excavation in which the electrical and water supply systems are to be arranged; the bottom and side walls of the excavation must be consolidated conveniently (arrangement of plinths and/or castings of concrete optionally reinforced with metallic nets).
The standard embodiment entails lining the walls of the excavation with suitable ceramic tiles, which are fixed by means of hydrophobic adhesives in order to prevent infiltrations into the concrete, which might damage the structure.
There are constructive solutions adapted to simplify installation: the excavation can in fact be lined with prefabricated panels (generally made of cement material), which are arranged in mutual contact until they surround the excavation perimetrically.
Waterproofing is obtained by lining the panels and the bottom of the pool with a sheath of polymeric material (generally polyvinyl chloride, PVC). The sheath is conveniently preformed and ensures adhesion to the walls and to the bottom without particular fixings: by virtue of the hydrostatic thrust provided by the water that fills the pool, the sheath is in fact compressed against the panels and the bottom.
This constructive solution, which is simple to apply, may not be welcomed by the user, since the tactile feeling of polymeric material is substantially different from the traditional feeling of tiles.
Secondly, installation (while being simplified with respect to traditional installation) is still complex and requires a perfect match between the design and its execution, on penalty of imperfect mating between the sheath and the walls/bottom.
One characteristic that is increasingly interesting for the buyer of a swimming pool or fountain or optionally of a pond is perfect aesthetic integration with the installation environment.
The built structure must therefore have a suitable shape (therefore the shape should be decided in each instance without any building constraint) and the materials that constitute it should have a color that harmonizes with the outside environment.
With the described constructive solutions, this is practically impossible: as regards traditional constructions, shape can be substantially modified at will and so can the choice of the color of the tiles of the cladding, but the labor and material costs can become prohibitive.
With the solution that provides the sheath made of polymeric material, the constructive limitations are evident: the prefabricated panels have preset shapes and dimensions and therefore force the choice of substantially mandatory installation criteria.